Various research and diagnostic techniques employ thermally-mediated chemical reactions such as the polymerase chain reaction (PCR), nucleic acid hybridization, and protein immunoassays and/or thermally-controlled environments for cell culture. Such techniques utilize a thermal cycler (also known as a thermocycler, PCR machine, and/or DNA amplifier). Thermal cyclers provide the high temperatures necessary to physically separate the strands of DNA double helix that is used as a template at lower temperatures for DNA synthesis by a DNA polymerase (e.g. Taq polymerase) to selectively amplify the target DNA.
Current methods for changing temperature of a liquid contained in a microtiter plate or sealed tube (e.g. Eppendorf tube or capillary tube) make use of an external, temperature-controlled liquid or solid to transfer heat into or extract heat from the liquid PCR reagents in an enclosed container. The primary limitation of this approach is the requirement for an intervening material between the energy source and the heated or cooled liquid. Miniaturization and scaling to larger numbers of liquid volumes to be heated and cooled is particularly problematic with the current art because of the dual design constraints of having to seal and heat/cool a large volumes of liquids contained in the well of a thermoplastic microtiter well plate.